Abstract

The development of high-performance electrode materials remains a critical challenge in the advancement of electrochemical supercapacitors for next-generation energy storage systems. In the present work, reduced graphene oxide (rGO) supported vanadium pentoxide nanocomposites doped with samarium ions were successfully synthesized through a simple co-precipitation route followed by thermal treatment. The structural, morphological, and electrochemical properties of rGO/V₂O₅:Sm³⁺ nanocomposites with different samarium concentrations (0, 3, 5, and 7 wt. %) were systematically investigated. X-ray diffraction analysis confirmed the formation of orthorhombic crystalline V₂O₅ with good phase purity, while structural parameters revealed crystallite sizes in the nanometres range. Scanning electron microscopy and high-resolution transmission electron microscopy studies indicated the formation of rod-like nanostructures uniformly distributed over conductive graphene sheets. Energy dispersive spectroscopy verified the presence of vanadium, oxygen, samarium, and carbon elements in the prepared nanocomposites without detectable impurities. Electrochemical properties of the synthesized materials were evaluated using cyclic voltammetry measurements in a three-electrode system with 2 M KOH electrolyte. The obtained cyclic voltammograms revealed characteristic redox peaks associated with the pseudo capacitive behaviour of vanadium oxide. The specific capacitance values calculated from the CV curves demonstrated a strong dependence on samarium doping concentration. Among the prepared samples, the rGO/V₂O₅:Sm³⁺ nanocomposite containing 7 wt. % samarium exhibited the highest specific capacitance of approximately 386.70 F g⁻¹. The enhanced electrochemical performance is attributed to the synergistic interaction between the conductive graphene network, the nanorod morphology of V₂O₅, and the lattice modification induced by samarium incorporation. Furthermore, the electrode displayed good cycling stability during repeated electrochemical cycling. The antibacterial activity of rGO/Pure V₂O₅ and Sm³⁺-doped rGO/V₂O₅ (7 wt. %) nanocomposites against Escherichia coli and Staphylococcus indicate that Sm³⁺ doping substantially improves the antibacterial performance. Thus, these findings suggest that rGO/V₂O₅:Sm³⁺ nanocomposites represent promising electrode materials for high-performance supercapacitor applications along with biomedical and cosmeceutical applications.

Keywords

Reduced Graphene Oxide, Vanadium Pentoxide, Samarium Doping, Nanocomposites, Electrochemical Supercapacitors, Electrochemical Energy Storage,

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